In a conventional hydrogen plant, shown in FIG. 1, PSA is used for separation of pure H2 from the syngas. The PSA tail gas is used as fuel in the reformer furnace. The heating value of the tail gas should be less than the firing duty of the reformer, otherwise there will be a surplus of tail gas. This requirement presents a constraint in the optimization of the hydrogen plant. The amount of methane slipping the reformer, and the amount of CO slipping the shift reactor has to be below a certain value to meet the constraint. The methane slippage from the reformer is a function of the temperature of the gas exiting the reformer (assuming the pressure and steam to carbon ratio is fixed). The steam is produced by recovering heat from the reformer process effluent as well as the reformer furnace flue gas. If the reformer temperature is increased to reduce methane slippage, the amount of steam made will also increase. The steam used for the process is constant, the export steam quantities increase. This is sometimes not desirable. If a part of the PSA tail gas can be recycled back to the process, the above mentioned constraint is lifted